The present invention relates generally to data storage devices and their associated positioning systems. In particular, it relates to data storage devices to store and recover data by producing optical, electrical, or mechanical changes in storage media at nanometer level (i.e., scale) increments (i.e., intervals) with microfabricated structures which are positionable at nanometer level increments with the positioning system of the data storage devices.
UV erasable programmable read only memories (UVPROMs) are well known to those skilled in the art. These types of memories comprise distinct charge storage cells or sites and include a separate read/write line to each of the charge storage cells. In order to write data to the UVPROM, it is first bulk erased by exposing simultaneously all of the charge storage cells to UV light or radiation to leak off any charges stored by them. Then, data is written to selected charge storage cells by injecting charges in them with the corresponding read/write lines. These charges may then be detected with the read/write lines so as to read data from the charge storage cells. Since UVPROMs include separate read/write lines to the charge storage cells, the charge storage cells are not able to be spaced apart at nanometer level increments so that the overall size of the UVPROM could be reduced. However, a UVPROM type structure with charge storage cells at nanometer level increments could be used if a mechanism were developed that could (1) selectively and individually write data to each charge storage cell by leaking off a charge in the charge storage cell with UV light, and (2) electrically read data from each storage cell by detecting or sampling a charge in the charge storage cell without a read line to the charge storage cell.
Moreover, recently attempts have been made at providing data storage devices where data can be electrically or mechanically written to and electrically read from a storage medium at nanometer level increments. However, these data storage devices all suffer from significant problems.
For example, U.S. Pat. No. 5,317,533, describes a data storage device utilizing scanning tunneling microscope (STM) probes to read and write data to a storage medium by producing and measuring tunneling currents between the STM probes and the storage medium. Furthermore, U.S. Pat. No. 5,289,408 describes a similar data storage device with a piezoelectric positioning apparatus for positioning STM probes over the storage medium to read and write data to the storage medium. This positioning apparatus is bulky and impractical to use as a part of a data storage device in a computing system. Moreover, since positioning of the STM probes over the storage medium in the X and Y directions is limited to the range of movement of the X and Y piezoelectric translator elements of the positioning apparatus, the storage capacity of this data storage device is also limited by this range of movement. And, to increase this range of movement so that the storage capacity of the data storage device is increased, the size of the X and Y piezoelectric translator elements must also be increased. This unfortunately increases the overall size, read/write times, weight, and power requirements of the data storage device.
Furthermore, U.S. Pat. No. 5,038,322 describes still another data storage device that utilizes STM probes. In this storage device, the STM probes are used to deform a deformable storage medium to write data to it which is represented by the deformations. Then, by producing and measuring a tunneling current between the STM probes and the storage medium, the deformations can be identified so as to read from the storage medium the data that was written to it. However, the STM probes comprise a soft conductive material, such as conductive silicon, tungsten, aluminum, or gold which wears down after prolonged use in deforming the storage medium. Thus, the useful life of this type of data storage device is limited.
The foregoing problems are solved by a data storage system that includes a positioning system for positioning the write/read mechanism and the storage medium of the data storage device with respect to each other in first and second predefined directions. The positioning system comprises a positioning apparatus comprising microfabricated first and second positioning assemblies.
The first positioning assembly includes a stationary support structure, a moveable support structure, a positionable support structure, a stationary support structure clamp, and a movable support structure clamp. The movable support structure is movably coupled to the stationary support structure and is moveable within a range of movement in a first predefined direction with respect to the stationary support structure. The positioning system further comprises a controller to position the positionable support structure in the first predefined direction within a range of positioning that is larger than the range of movement of the moveable support structure. It does so by controlling (A) the stationary support structure clamp in clamping and unclamping the positionable structure to and from the support structure, (B) the moveable structure clamp in clamping and unclamping the positionable support structure to and from the moveable support structure, and (C) the movement of the moveable support structure.
In one embodiment, the second positioning assembly comprises a stationary support structure and a moveable support structure. The movable support structure is movably coupled to the stationary support structure and is moveable within a range of movement in a second predefined direction with respect to the stationary support structure. The controller controls the positioning of the moveable structure in the second direction within the range of movement of the moveable structure. In another embodiment, the second positioning assembly may be constructed and controlled in the same way as the first positioning assembly.
In one embodiment, one of the write/read mechanism and the storage medium is carried by the positionable support structure so that it is positioned with the first positioning assembly. The other one of the write/read mechanism and the storage medium is positioned with the second positioning assembly. In another embodiment, the positionable support structure carries the second positioning assembly and one of the write/read mechanism and the storage medium is positioned with the second positioning assembly while the other is held stationary.
In one embodiment, the storage medium is deformable and the write/read mechanism comprises one or more write probes and one or more read probes. The write probes each include a write tip with a highly obdurate coating capable of deforming the storage medium and a write tip positioning apparatus to lower the write tip. The read probes each include a conductive read tip. The controller is used to (A) during a write mode, control the first and second positioning apparatus in positioning the write probes over the storage medium, (B) during the write mode, control each write tip positioning apparatus in lowering the corresponding write tip a predetermined amount into the storage medium so as to cause a predetermined amount of deformation in the storage medium representing data written thereto, (C) during a read mode, control the first and second positioning apparatus in positioning the read probes over the storage medium, and (D) during the read mode, produce and measure a tunneling current between each conductive read tip and the storage medium to identify a predetermined amount of deformation caused in the storage medium during the write mode so that the data written thereto is read therefrom.
In another embodiment, the data storage device comprises one or more probes each comprising a tip with a conductive highly obdurate coating capable of deforming the storage medium and a tip positioning apparatus to lower the tip. The controller in this embodiment is used to (A) during a write mode, control the probe and storage medium positioning apparatus in positioning the probes over the storage medium, (B) during the write mode, control each tip positioning apparatus in lowering the corresponding tip a predetermined amount into the storage medium so as to cause a predetermined amount of deformation in the storage medium representing data written thereto, (C) during a read mode, control the probe and storage medium positioning apparatus in positioning the probes over the storage medium, (D) during the read mode, control each tip positioning apparatus in lowering the corresponding tip close to the storage medium, and (E) during the read mode, produce and measure a tunneling current between the conductive obdurate coating of each tip and the storage medium to identify a predetermined amount of deformation caused in the storage medium during the write mode so that the data written thereto is read therefrom.
In still another embodiment, the data storage device comprises a storage medium alterable by light, one or more light emitting write probes each capable of emitting light, and one or more read probes each capable of detecting alterations of the storage medium caused by light. The controller is used in this embodiment to (A) during a write mode, control the positioning apparatus in positioning the write probes over the storage medium so that the light emitting write tips are over the storage medium, (B) during the write mode, control each light emitting write probe to emit a predetermined amount of light so as to cause a predetermined amount of alteration of the storage medium so as to write data thereto, (C) during read modes, control the positioning apparatus in positioning the read probes over the storage medium so that each read probe detects a predetermined amount of alteration of the storage medium caused during the write mode, and (D) during the read mode, measure each detected predetermined amount of alteration of the storage medium so that the data written to the storage medium during the write mode is read therefrom.
In yet another embodiment, the data storage device comprises an electrically alterable storage medium, a triangular ridge support structure, one or more conductive triangular ridges on the base structure, and an acoustic wave generator on one of the triangular ridge support structure and the storage medium to produce surface acoustic waves thereon that propagate in a direction parallel to the axial length of the triangular ridges. The controller in this embodiment is used to (A) during a write mode, control the positioning apparatus in positioning the triangular ridge support structure over the storage medium so that each triangular ridge is over a corresponding region of the storage medium to be written, (B) during the write mode, control the acoustic wave generator to produce an acoustic wave, (C) during the write mode, apply at a predetermined time across each triangular ridge and the storage medium a voltage pulse having a predetermined voltage and duration while the acoustic wave produced during the write mode propagates so that a portion of the triangular ridge above the corresponding region to be written is displaced down theretoward and the corresponding region to be written is electrically altered by a predetermined amount, (D) during a read mode, control the positioning apparatus in positioning the triangular ridge support structure over the storage medium so that each triangular ridge is over a corresponding region of the storage medium to be read, (E) during the read mode, control the acoustic wave generator to produce an acoustic wave, (F) during the read mode, with each triangular ridge at a predetermined time while the acoustic wave produced during the read mode propagates so that a portion of the triangular ridge above the corresponding region to be read is displaced down theretoward, detect a predetermined amount of electrical alteration of the corresponding region to be read caused during the write mode, (G) during the read mode, measure each detected predetermined amount of electrical alteration of the corresponding region to be read so that the data written thereto during the write mode is read therefrom.
In still yet another embodiment, the positioning system is used in a biochemical instrument. The biochemical instrument comprises a probe that includes a porous tip and a tip positioning apparatus to position the tip with respect to a sample material. The positioning apparatus is used to position the probe and sample material with respect to each other. The controller is used to (A) control the positioning apparatus in positioning the probe over the sample, and (B) control the tip positioning apparatus in lowering the tip into the sample material to produce a biochemical interaction between the porous tip and the sample material.